TEHRAN - Iran is to host a high-level team from the UN nuclear watchdog on Monday as part of efforts to defuse dire international tensions over its atomic activities through dialogue.

But other words being spoken in Israel, the United States and Britain - and Iran's defiant moves to boost its nuclear activities - underlined the prospect of possible Israeli military action against the Islamic republic.

Iran also signalled on Sunday that it is ready to hit back hard at sanctions threatening its economy, by announcing it has halted its limited oil sales to France and Britain.

Iranian Foreign Minister Ali Akbar Salehi on Sunday said his country was keen to quickly resume mooted talks with world powers, once a place and date were agreed.

The last talks collapsed in Istanbul in January 2011, but Iran has responded positively to an EU offer to look at reviving them. "We are looking for a mechanism for a solution for the nuclear issue in a way that it is win-win for both sides," Salehi said. But he added that Iran remained prepared for a "worst-case scenario."

Such a scenario - war - remained very much the subtext of a visit to Israel on Sunday by US National Security Advisor Tom Donilon. Israel has been gripped by speculation in recent weeks that it is closer to mounting a pre-emptive strike on Iran's nuclear programme, though Tel Aviv has denied reaching such a decision. The United States, while not ruling out its own possible military option against Iran, was publicly being seen holding back its main Middle East ally from taking such drastic action.

"I think it would be premature to exclusively decide that the time for a military option was upon us," the chairman of the US Joint Chiefs of Staff, General Martin Dempsey, told CNN.